org.basex.query.expr
Class Simple

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.expr.Expr
          org.basex.query.expr.Simple

Direct Known Subclasses:

Context, FTIndexAccess, IndexAccess, Pos, Root

public abstract class Simple
extends Expr

Simple expression without arguments.

Author:

Workgroup DBIS, University of Konstanz 2005-09, ISC License, Christian Gruen

Constructor Summary

Simple()

Method Summary

java.lang.String	color() Returns a string description of the expression.
Expr	comp(QueryContext ctx) Optimizes and compiles the expression.
void	plan(Serializer ser) Recursively sends the abstract syntax of this expression to the specified serializer.
boolean	uses(Expr.Use use, QueryContext ctx) Indicates if an expression uses the specified type.

Methods inherited from class org.basex.query.expr.Expr

addText, atomic, checkCtx, checkDbl, checkItr, duplicates, e, ebv, i, indexAccessible, indexEquivalent, iter, removable, remove, returned, sameAs, size, test

Methods inherited from class org.basex.query.ExprInfo

info, name, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Simple

public Simple()

Method Detail

comp

public Expr comp(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Optimizes and compiles the expression.

Specified by:

comp in class Expr

Parameters:

ctx - query context

Returns:

optimized Expression

Throws:

QueryException - evaluation exception

uses

public boolean uses(Expr.Use use,
                    QueryContext ctx)

Description copied from class: Expr

Indicates if an expression uses the specified type. Called by the compiler to perform certain optimizations. true is returned by default and thus assumed as "worst-case".

Overrides:

uses in class Expr

Parameters:

use - use type to be checked

ctx - query context

Returns:

result of check

color

public java.lang.String color()

Description copied from class: ExprInfo

Returns a string description of the expression. Contrary to the ExprInfo.toString() method, the current expressions aren't included in the output.

Overrides:

color in class ExprInfo

Returns:

result of check

plan

public void plan(Serializer ser)
          throws java.io.IOException

Description copied from class: ExprInfo

Recursively sends the abstract syntax of this expression to the specified serializer.

Specified by:

plan in class ExprInfo

Parameters:

ser - serializer

Throws:

java.io.IOException - exception